The embodiment relates to a pixel capable of individually distinguishing between visible and non-visible wavelength bands, a pixel array, an image sensor including the same, and a method for operating the image sensor. In particularly, the embodiment relates to a pixel capable of more simply distinguishing between lights having wavelength bands different from each other to detect the lights by additionally arranging a potential control switching section at one side of a photodiode.
Conventionally, an IR cut filter has been used in a camera module to filter lights having infrared wavelength bands, thereby sensing only lights in visible wavelength bands, so that image processing can be clearly performed. This is because it is difficult for an image sensor employing a silicon substrate to process mixed image signals obtained from both visible lights and infrared lights.
However, as a digital camcorder and a cellular phone have been popularized, infrared lights as well as visible lights must be exactly detected. Accordingly, an imaging apparatus equipped with an infrared image sensor together with a color image sensor has been increased. Hereinafter, the technologies of sensing infrared lights will be briefly described.
First, a predetermined layer may be inserted around an RGB color filter on a photodiode constituting an image sensor to transmit only wavelength bands of infrared lights. However, the technology of inserting the layer to transmit only the infrared lights may not be actually applied to a semiconductor device process.
Second, a scheme of distinguishing between visible and infrared image signals by performing an operation for mixed signals of the visible and infrared image signals after both visible lights and infrared lights are applied to one sensor. However, since an additional operation module for image processing of the mixed signals has a complex structure, the image processing of the mixed signals may be inconvenient.